As the proto-continents floated around, they sometimes collided and stuck together, a process called accretion.
Early in Earth’s history, all of the continents came together to form one giant continent. This occurred in the Proterozoic era, about 1,250 million years ago. At the time, there was only unicellular (one-celled) life on Earth.
That continent broke up, but much later, in the Permian period (270 million years ago), a continent scientists call Pangaea formed. Life at this time consisted of invertebrates, fish, and amphibians.
About 230 million years ago, Pangaea split into two large continents: Laurasia, which included North America, Greenland, and Eurasia; and Gondwanaland, which included South America, Africa, Australia, and Antarctica.
This split happened just before the age of the dinosaurs. About 80 million years ago, at the end of the Cretaceous period, the land masses began to split up to resemble what we are familiar with today.